The award is a victory for Raytheon over rivals Lockheed Martin Corp. and Northrop Grumman Corp., two of the other major makers of sophisticated radar systems that were vying for the contract. It’s also critical at a time of overall defense spending cuts that have taken a toll on military contractors.

“Raytheon has once again secured business in a new area at a time when rivals are seeing their revenues decline,” said Loren Thompson, a defense analyst with the Lexington Institute in Washington. “It’s nearly impossible to grow market share in a defense downturn, and Raytheon is managing to do it.”

In July, Raytheon won a highly competitive $270 million contract with the Navy to build electronic jamming systems for fighter jets, a deal that could eventually be worth billions of dollars, said Thompson.

The most recent agreement with the Navy is to develop, test, and deliver next-generation air and missile defense radars for the Navy’s Flight III Arleigh Burke destroyers. The radars will be designed to more accurately detect long-range missiles and other incoming threats, and are expected to be ordered in 2019.

Raytheon’s systems are being designed to outfit at least 22 naval ships, half of which are being built at General Dynamics Corp.’s Bath Iron Works in Bath, Maine.

Work on the radar systems will be conducted at Raytheon’s facilities in Andover and Sudbury. While the company would not say whether the contract will immediately result in new jobs, defense analyst Thompson expects Raytheon to hire hundreds of workers to complete the project. Raytheon has a global workforce of about 68,000 and is one of Massachusetts’ biggest employees.

The contract with the Navy was not a casualty of the government shutdown since the initial money for it was appropriated prior to the closure. The base contract value is $385 million, but it includes options that could increase the value to $1.6 billion.

The radar is one of the most expensive and advanced such systems the Navy has ever ordered, said Chris Johnson, spokesman for Naval Sea Systems Command.

And as for the government workers responsible for the final sign-off on the deal, he said, they aren’t on the list of furloughed workers.